Problem: Simplify the expression. $(-5y-7)(-3y+4)$
First distribute the ${-5y-7}$ onto the ${-3y}$ and ${4}$ $ = {-3y}({-5y-7}) + {4}({-5y-7})$ Then distribute the ${-3y}.$ $ = ({-3y} \times {-5y}) + ({-3y} \times {-7}) + {4}({-5y-7})$ $ = 15y^{2} + 21y + {4}({-5y-7})$ Then distribute the ${4}$ $ = 15y^{2} + 21y + ({4} \times {-5y}) + ({4} \times {-7})$ $ = 15y^{2} + 21y - 20y - 28$ Finally, combine the $x$ terms. $ = 15y^{2} + y - 28$